Systems And Methods For Multi-Zone Power And Communications

ABSTRACT

A system, method and device may be used to provide power and monitor conditions in a borehole. Well tubing and casing act as a conductive pair for delivering power wirelessly to isolated zones defined between packer elements. Data signals are similarly transmitted. The packer elements include magnetic toroidal cores for power and signal transmission via inductively coupling.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 to U.S.Provisional Patent Application Ser. No. 62/349,769, titled “Systems andMethods For Multi-Zone Power and Communications” and filed on Jun. 14,2016, the entire contents of which are hereby incorporated herein byreference.

TECHNICAL FIELD

The present application relates generally to power and data transmissionin a multi-zone completion environment using unique magnetic couplingtechnology.

BACKGROUND

In resource recovery, it may be useful to supply electrical power andmonitor various conditions at locations in a wellbore (also calledherein a “borehole”) remote from an observer. In particular, it may beuseful in completions and production operations to provide power andmonitor temperature, pressure, fluid velocity or flowrate, and/or fluidcharacteristics within isolated zones between packer elements in awellbore. However, it can be difficult or inconvenient to deliver powerin such environments. In some cases, electrical cables are installed inthe wellbore extending across each zone, but such cables sometimes aredifficult and expensive to install and maintain in an operationallysecure manner. In addition, it can be difficult to install a cable inthe confined space of an isolated zone. Additionally, such cables maybecome eroded or damaged during installation or during use. Such damagemay require costly workovers and delays in oil and gas production.

Wireless transmission of power and data has also not been an option fortransmitting into isolated zones between the packer elements in awellbore. Packer elements generally include sealing glands and metallicslips to seal the packer element in position in the annulus and toisolate zones within a wellbore. The metallic components of the packerelements would short out any electrical or signal path from the surfaceto the casing upon setting however, and thus current and signal cannotflow wirelessly from the surface, past the packer elements, and down thecasing.

Because such boreholes may extend several miles, eliminating some of thewires associated with power and sensor technology becomes desirablesince it is not always practical to replace power sources or cables usedin conventional boreholes.

SUMMARY

In general, in one aspect, the disclosure relates to a packer assemblyfor disposal within a subterranean wellbore lined by a casing. Thepacker assembly can include a packer having an upper end, a lower end,and a feedthrough that traverses the packer from the upper end to thelower end, where the upper end is configured to couple to a first tubingstring, where the lower end is configured to couple to a second tubingstring. The packer assembly can also include a first core disposedaround the second tubing string adjacent to the lower end of the packer.The packer assembly can further include an electrical wire disposedwithin the feedthrough of the packer, where the electrical wire has aproximal end and a distal end wrapped around the first core. Theproximal end of the electrical wire can be configured to receive a firstpower from a power source disposed above the upper end of the packer,where the distal end of the electrical wire is configured to use thefirst power to induce a second power in the first core, where the secondpower in the first core generates a first current that flows on thesecond tubing string away from the first core.

In another aspect, the disclosure can generally relate to a powertransmission system for use within in a subterranean wellbore having acasing disposed against a subterranean formation and defining an outerperimeter of the subterranean wellbore and forming a cavity. The systemcan include a power source disposed proximate to a surface at an openingof the subterranean wellbore, where the power source generates a firstpower. The system can also include a first tubing string segmentdisposed within the cavity. The system can further include a firstpacker mechanically coupled to a first distal end of the first tubingstring within the cavity of the subterranean wellbore, where the firstpacker has a first feedthrough disposed therein along a first height ofthe first packer. The system can also include a second tubing stringsegment mechanically coupled to a first bottom end of the first packerwithin the cavity of the subterranean wellbore. The system can furtherinclude a first core disposed around the second tubing string segmentadjacent to the bottom end of the first packer and the firstfeedthrough. The system can also include a first electrical wiredisposed within the first feedthrough of the first packer, where thefirst electrical wire has a first end coupled to the power source and asecond end wrapped around the first core, wherein the first electricalwire receives the first power from the power source. The first powerflowing through the first electrical wire disposed around the first corecan induce a second power in the first core, where the second power inthe first core generates a first current that flows on the second tubingstring away from the first core further into the subterranean wellbore.

These and other aspects, objects, features, and embodiments will beapparent from the following description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate only example embodiments of systems and devicesfor transmitting power and data to isolated zones in a subterraneanwellbore and are therefore not to be considered limiting of its scope,as transmitting power and data to isolated zones within a wellbore mayadmit to other equally effective embodiments. The elements and featuresshown in the drawings are not necessarily to scale, emphasis insteadbeing placed upon clearly illustrating the principles of the exampleembodiments. Additionally, certain dimensions or positionings may beexaggerated to help visually convey such principles. In the drawings,reference numerals designate like or corresponding, but not necessarilyidentical, elements.

FIG. 1 is a schematic diagram of a field system having wireless powerand data transmission capabilities within zones in a subterraneanwellbore, according to an example embodiment.

FIGS. 2A-2C show a circuit diagram and two schematic diagrams,respectively, that includes a core according to an example embodiment.

FIG. 3 is a current flow schematic at a downhole packer assembly,according to an example embodiment.

FIG. 4 is an illustration showing how magnetic coupling works in a casedwell construct, according to an example embodiment.

FIG. 5 is a cross-sectional schematic showing a magnetic field generatedby current sheets that surround a magnetic toroidal core, according toan example embodiment.

FIG. 6 is a close-up schematic of a midstream portion of an isolatedzone, showing another case of current sheets on tubing and inside of acasing wall, according to an example embodiment.

FIG. 7 is a close-up schematic of a midstream portion of an isolatedzone, having a sensor system placed along a cell or zone region alongtubing, according to an example embodiment.

FIG. 8 is a schematic diagram of a three-zone field system, broken up tofit the page, according to an example embodiment.

FIG. 9A is a schematic of a packer assembly with embedded inductivecoupling and sensors, in an unset position, according to an exampleembodiment.

FIG. 9B is a schematic of the packer assembly of FIG. 9A, in setposition, according to an example embodiment.

FIG. 10 is a schematic of a single zone simulator for laboratory testingpurposes, according to an example embodiment.

FIG. 11 is a schematic of a dual-zone simulator for laboratory testingpurposes, according to an example embodiment.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Example embodiments directed to methods, systems, and devices forinductively coupled power and data transmission to isolated zones in asubterranean wellbore will now be described with reference to theaccompanying figures. Like, but not necessarily the same or identical,elements in the various figures are denoted by like reference numeralsfor consistency. In the following description of the exampleembodiments, numerous specific details are set forth in order to providea more thorough understanding of the disclosure herein. However, it willbe apparent to one of ordinary skill in the art that the exampleembodiments herein may be practiced without these specific details. Inother instances, well-known features have not been described in detailto avoid unnecessarily complicating the description.

A user as described herein may be any person that is involved with apiping system in a subterranean wellbore and/or transmitting power anddata within the subterranean wellbore for a field system. Examples of auser may include, but are not limited to, a roughneck, a companyrepresentative, a drilling engineer, a tool pusher, a service hand, afield engineer, an electrician, a mechanic, an operator, a consultant, acontractor, and a manufacturer's representative.

If a component of a figure is described but not expressly shown orlabeled in that figure, the label used for a corresponding component inanother figure can be inferred to that component. Conversely, if acomponent in a figure is labeled but not described, the description forsuch component can be substantially the same as the description for thecorresponding component in another figure. The numbering scheme for thevarious components in the figures herein is such that each component isa three or four digit number and corresponding components in otherfigures have the identical last two digits.

In the foregoing figures showing example embodiments of wireless powerand data transmission systems, one or more of the components shown maybe omitted, repeated, and/or substituted. Accordingly, exampleembodiments of wireless power and data transmission systems should notbe considered limited to the specific arrangements of components shownin any of the figures. Further, any description of a figure orembodiment made herein stating that one or more components are notincluded in the figure or embodiment does not mean that such one or morecomponents could not be included in the figure or embodiment, and thatfor the purposes of the claims set forth herein, such one or morecomponents can be included in one or more claims directed to such figureor embodiment.

Terms such as “first”, “second”, “primary”, “secondary”, “top”,“bottom”, “side”, “width”, “length”, “upper”, “lower”, “above”, “below”,“inner”, and “outer” are used merely to distinguish one component (orpart of a component or state of a component) from another. Such termsare not meant to denote a preference or a particular orientation, andare not meant to limit embodiments of wireless power and datatransmission systems described herein.

FIG. 1 shows a schematic diagram of a field system 100 that can transmitpower and data in a subterranean wellbore 102 during completions and/orproduction operations in accordance with one or more exampleembodiments. Referring now to FIG. 1, the field system 100 in thisexample includes a completed wellbore 102 within a subterraneanformation 104 below a ground surface 108. The point where the wellbore102 begins at the surface 108 can be called the entry point. Thesubterranean formation 104 can include one or more of a number offormation types, including but not limited to shale, limestone,sandstone, clay, sand, and salt. In certain embodiments, a subterraneanformation 104 can also include one or more reservoirs in which one ormore resources (e.g., oil, gas, water, steam) can be located. One ormore of a number of field operations (e.g., drilling, setting casing,extracting downhole resources) can be performed to reach an objective ofa user with respect to the subterranean formation 104.

The wellbore 102 can have one or more of a number of segments, whereeach segment can have one or more of a number of dimensions. Examples ofsuch dimensions can include, but are not limited to, size (e.g.,diameter) of the wellbore 102, a curvature of the wellbore 102, a totalvertical depth of the wellbore 102, a measured depth of the wellbore102, and a horizontal displacement of the wellbore 102. Surfaceequipment 114 can be used to create and/or develop (e.g., extractdownhole materials) the wellbore 102. The surface equipment 114 can bepositioned and/or assembled at the surface 108. The surface equipment114 can include, but is not limited to, a power source 195 and otherequipment for multi-zone completions, where the zones 120 are definedbelow.

Included in the field system 100 of FIG. 1 is an example power deliverysystem 190. A completed wellbore 102 can include a casing string 109that defines the outer perimeter of the wellbore 102 and a productiontubing 110 disposed within the cavity 188 (also called an annular volumeherein) formed by the casing string 109. Extracted downhole materialscan flow through the production tubing 110 towards the surface equipment114. The casing string 109 and the production tubing 110 are generallyelectrically conductive. The wellbore 102 can include a number ofperforated zones 120 isolated from one another via isolation packerelements 124 a, 124 b, . . . 124 n (referred to collectively herein asisolation packer elements 124, where n refers to the packer closest tothe toe or distal end of the wellbore 102). Each packer element 124 isdisposed within the cavity 188 between the tubing 110 and the casingstring 109. A zone 120 can be part of one or more segments of thewellbore 102. In addition, or in the alternative, a segment of thewellbore 102 can include one or more zones 120.

In this example, an electric line or cable 126 extends from a systempower source 195 above the surface 188 to a production packer element128. The packer element 128 is also disposed within the cavity 188between the tubing 110 and the casing string 109. In certain exampleembodiments, the production packer element 128 and the isolation packerelements 124 are feedthrough packers. In other words, the productionpacker element 128 and the isolation packer elements 124 can includefeedthrough, channel, or other pathway to allow a component (e.g., anelectrical cable or electrical conductors) of an example wireless powerand data transmission system to pass therethrough. In this case, theproduction packer element 128 has feedthrough 125, and each of theisolation packer elements 124 (with the exception of isolation packerelement 124 n) has feedthrough 126.

Generally, in certain example embodiments, the production packer element128, by virtue of the cable 126 disposed in the feedthrough 125, is inelectrical communication with a first magnetic toroidal core 130, andthe first magnetic toroidal core 130 in turn transmits currentswirelessly via the electrically-conductive production tubing 110 to anupper magnetic toroidal core 132 a that is electrically coupled toisolation packer element 124 a. Power can then be transmitted via wiring(hidden from view) from the upper magnetic toroidal core 132 a throughthe feedthrough 126 a of isolation packer element 124 a to a lowermagnetic toroidal core 136 a in an adjacent zone 120.

The lower magnetic toroidal core 136 a in turn transmits currentswirelessly via the electrically-conductive production tubing 110 to anupper magnetic toroidal core 132 b that is electrically coupled toisolation packer element 124 b. Power can then be transmitted by wiringdisposed within the feedthrough 126 b of the isolation packer element124 b to a lower magnetic toroidal core 136 b in the next zone.Generally, power can be transmitted within a number of isolated zones120 from a lower magnetic toroidal core 136 to an upper magnetictoroidal core 132 in this manner. Similarly power can be transmittedacross adjacent zones 120 using wiring disposed within the feedthroughs126 of the corresponding isolation packer elements 124, where one end ofthe wiring is coupled to an upper magnetic toroidal core 132 and theother end of the wiring is coupled to a lower magnetic toroidal core136.

More specifically, by transformation of magnetic fields in an uppermagnetic toroidal core 132 to a “secondary winding” on the core, thetransformed current is manifested in the wire of the winding andpenetrated through isolation packer element 124 to the lower side of thepacker element 124 via an insulated and pressure sealed feed-through.This wire carrying the secondary current is then attached to a similarwinding on lower magnetic toroidal core 136 on the lower side of thepacker element 124 that will launch current down the production tubing110 within that zone 120 below that packer element 124. By replicationof this technique at each isolation packer element 124, power may betranslated through several electrically isolated zones 120, without theuse of annulus-located cabling. In addition to power/current, data canalso be similarly transmitted across the zones 120 using thistransmission system. Absent the wiring in the feedthrough 126, thetubing 110 in a zone 120 is electrically isolated from the tubing 110 inan adjacent zone 120 by the isolation packer element 124 that separatesthose two zones 120.

FIGS. 2A, 2B, and 2C show a wiring diagram, a schematic diagram, andanother schematic diagram, respectively, involving a core 232 of anexample power delivery system according to certain example embodiments.Referring to FIGS. 1, 2A, 2B, and 2C, in certain embodiments, the core232 is toroidal and interacts with two wires 257 (wire 257-1 and wire257-2) of an electrical cable 256. Wire 257-1 carries inbound currentand is wound around the core 232 multiple times. The current flowingthrough wire 257-1 induces a current-generated magnetic field (H-field)vector within the core, which in turn induces a current sheet that flowsaxially through the center of the core 232. When a tubing pipe 210 isdisposed through the center of the core 232, this current sheet flowsalong the tubing pipe 210. When there is an electrical short (discussedbelow) between the tubing 210 and the adjacent casing 209, then thecurrent that flows along the tubing 210 returns along the casing 209.The distal end of wire 257-1 and wire 257-2 are joined together,essentially creating a continuous wire 257. Wire 257-2 carries thereturn or outbound current back through the cable 256 to the source ofthe current.

In FIG. 2C, the schematic of FIG. 2B is expanded. Specifically, thecontinuous wire 257 is shown partially disposed within a feedthrough 226of a packer 224. Wire 257-1 and wire 257-2 can be in the samefeedthrough 226, or the packer can have multiple feedthroughs 226, withwire 257-1 being disposed in one feedthrough 226 and wire 257-2 beingdisposed in the other feedthrough 226. The wire 257 in this case is asingle continuous wire that wraps around core 232 at one end of thepacker, and that also wraps around core 236 at the other end of thepacker. The packer 226 electrically isolates zone 220 a from zone 220 b.As a result, the current induced through core 232 flows in a loopbetween tubing 210 and casing 209 within zone 220 b, and the currentflowing in a loop along tubing 210, through core 236, and returningalong the casing 209 induces current in the wire 257 wrapped around core236 within zone 220 a.

FIG. 3 illustrates a typical current flow scheme at a packer assembly370 according to certain example embodiments. Referring to FIGS. 1-3,the packer assembly 370 includes a packer element 324 and at least oneother component. In this case, the packer assembly 370 includes thepacker element 324, toroid 332, toroid 336, and a number ofelectrically-conductive cleats 371 disposed along the outer perimeter ofthe packer element 324. When the tubing 310 is coupled to the packerassembly 370, the cleats 371 make an ohmic (resistive) connection to thetubing string 310. In other words, there is electrical continuitybetween the cleats 371 and the tubing 310 when the tubing 310 is coupledto the packer assembly 370. The cleats 371 can be protracted when thepacker assembly 370 is disposed at a desired location within thewellbore. When this occurs, the cleats 371 make contact with the casing309 and create the short 375, which provides a return path for thecurrent that originates from the power source (e.g., power source 195)and flows through the tubing 310. The cleats 371 also mechanicallyanchor the packer assembly 370 to the casing 309.

Current in zone 320-1 on production tubing 310 above packer assembly 370induces an attendant magnetic field in an upper magnetic toroidal core332 (enhanced by the special core material). In certain exampleembodiments, the current path 385 in the tubing-casing skins constitutesone full turn of a distributed winding (on the associated toroidalcore), a winding we will here dub, ‘primary’ winding, as current in theproduction tubing 310 returns back in the casing 309 inner diameter (ID)skin and passes the upper magnetic toroidal core 332 inside and outsidethat core 332. There is a wire winding of several turns on the uppermagnetic toroidal core 332 that is considered a ‘secondary’ winding.

One or more leads (also called wires herein) from this secondary windingare fed through the packer assembly 370 housing in a sealed feedthrough326 to the other (lower) side of the packer assembly 370. The one ormore wires are hidden from view in this example. If shown, there can bea single continuous wire that wraps around core 332 and core 336, whilea remainder of the wire is disposed within the feedthrough 326. Thiswinding in the upper magnetic toroidal core 332 then drives a similarwinding on a lower magnetic toroidal core 336, inducing a current in acurrent path 385-2 on the production tubing 310 in the string section(zone 302-2) below this packer assembly 370. In certain exampleembodiments, the packer assembly 370 is manufactured with the uppertoroidal core 332 and the lower magnetic toroidal core 336 integratedand wired in, and can be assembled on site by the completion crew in aconventional manner with no special techniques required.

In certain applications, the winding turn ratios of each magnetictoroidal core (e.g., core 332, core 336) allow the advantage ofrelatively high current in the production tubing 310, and thus lowvoltage between the production tubing 310 and casing 309 so that theinsulation requirements of the wellbore annulus (cavity 388) arereduced. Some salt-based packer fluids may have adequately highresistive nature for manageable system power loss, reducing some of the“insulative” character of a possible needed packer fluid. Some highdensity packer fluids may become more ‘conductive’ as an electricalconductor as the density and salt character increases. This may or maynot pose a challenge for the power and communications ability of aparticular zone 320, but should be considered in the early design phasefor the completion.

FIG. 4 illustrates how magnetic coupling works in a cased wellconstruct. Referring to FIGS. 1-4, magnetic coupling occurs where theH-field is ‘collected’ by the internal toroidal core magnetic material,intersected by the current-generated magnetic field (H-field) vector 451shown in FIG. 4. Electrical current always generates an attendantmagnetic field, as explained by Faraday's Law of Induction. These cores(e.g., core 332) use materials in their bulk that have a highsusceptance′ to magnetic fields that, in a way, concentrate availablefield density. The toroidal shape of the core can be used to act as amagnetic antenna in this application, where the system current 486follows the current path 485 defined as being on the tubing surface 410and returning on the inside of the casing 409, effectively fully wrappedaround the toroidal core.

In certain example embodiments, an effective magnetic ‘antenna’ in thepresent application may be a toroidal, magnetic core with the largestouter diameter (OD) possible (as large as the ‘drift’ diameter) and thetightest possible fit around the outer surface of the tubing 410. Thecloser the “skin” current flow is to the core magnetic material, thebetter the coupling to the magnetic fields is, and the effectivepower-loss per coupling is reduced. Limitations on these mechanicaldimensions are understood by one having ordinary skill in the art forapplicable and safe, useable packer designs. It should be noted thatthis is specifically an alternating current (AC) current application;direct current (DC) current will not transfer power continuously inthese example power transmission systems using magnetically coupledapplications.

The current (I) 486 runs along the surface of the tubing 410 and on theinside surface of the casing 409 to form the current path 485 in acomplete loop. The bulk of the current flows in a thin outer layer ofthe conductive metals, generally referred to as the current“skin-depth”. The depth or cross-section of the metal conductor whereconduction is present improves as the skin-thickness increases (lowerZ-axis resistance per unit length) deeper into the wall of the conductor410. The effective thickness gets thinner as the operating frequency ofthe current 486 increases. In certain example embodiments,communications may be operated at lower frequencies as these losses arereduced as that “skin” gets thicker. In certain embodiments, where powerrequirements increase, power is transmitted at frequencies of 400-2000Hz and lower.

As shown in FIG. 4, the dashed line portion of the current path 485implies circuit completion at a hanger or packer to the right of thedrawing, where the tubing 410 and casing 409 become electricallyconnected or terminated by another packer or device that brings thetubing 410 and casing 409 in electrical connection. There are a numberof options available for initial power and communications feed at theground level including “hot-string” techniques described, for example,in U.S. Pat. No. 9,316,063, to the customary cabled drop from hanger totop packer.

FIG. 5 illustrates additional details of the magnetic field generated bythe current sheets that surround a magnetic toroidal core cross-section.Referring to FIGS. 1-5, the current 586 in the production tubing 510 andthe inside wall of the casing 509 are wave-generated and “coherent”,which means that, at any point in time, they are opposite in direction,the same in signal timing, and essentially wrap around the magneticmaterial of the core 532. The coaxial construct of a classic wellproduces a wave guide, thus the currents (both power and communications)are the result of a “traveling wave”. This forces the E-field andmagnetic field (shown by magnetic field vector 551 in FIG. 5) into theannular volume 588 of the guide away from the two conductors (in thiscase, the tubing 510 and the casing 509). Current remains in the ‘skin’of these conductors. This simplifies the skin-depth calculation as thereis no magnetic term in that skin-depth calculation. In other words,there is no further loss due to magnetic materials (steel, etc.) in thetubing 510 and the casing 509.

In addition, the ‘sheet-current’ (represented by the current 586 in thetubing 510 in FIG. 5 and normally called ‘J’), is the current densitywhere current 586 is the integral of J over the conductive areainvolved. The core material in the cores 532 (or other cores, such ascore 336) described herein may be made of various alloys of ferrite or aspecial metal tape, such as layers of magnetic grade iron alloy thatcapture and concentrate the field inside the effective current loop. Incertain example embodiments, a copper winding 557 for the ‘secondaries’may be employed around the core 532 to improve efficiency. The type ofmaterial of the core 532 can depend on one or more of a number offactors. For example, the type of material of the core 532 can depend onthe frequencies expected for both power and communications.

The induced voltage in the attached, multi-turn winding 557 (core“secondary”) is transformed from the voltage between the tubing 510 andthe casing 509 (effectively one turn) to a voltage that is multiplied bythe number of secondary turns (e.g. five turns) that are wound aroundthe cross-section of the core 532. At the same time the current in thatmulti-turn winding 557 is one-fifth (for five secondary turns) thecurrent 586 in the current sheet of the tubing 510. The power equationremains the same in that what was reduced in current is balanced by thefive-times (for five secondary turns) increase in voltage. In certainembodiments, the “traveling wave” idea also supports the possibility ofhaving a core 532 placed anywhere along the tubing 510 between packersused as a coupler to the system power/communication stream. The waveexists all along the zone or cell structure and makes the connection topower and signals in that wave easily accessible.

Liquids and solids can present a resistive path across the annularvolume 588 between the tubing 510 and casing 509 (a ‘shunt-current’path) that will spill off power to heating material (e.g., brine, saltincluded fluids) in the annular volume 588. A packer fluid that has abulk electrical resistive character would shift the equation. Systemdesigners would favor high current 586 on the tubing 510, less voltageacross the annulus 588. That annular power loss is quantified by theequation P₁=E²/R where the R is the effective resistance, tubing 510 tocasing 509, of the annulus volume 588. If the R is very large (toward anopen circuit), the losses to the annular volume 588 are very low. Theadvantage of the above magnetically coupled zone transformationresulting from the cores (e.g., core 532) having a large turns-ratioputs high current 586 on the tubing 510 and very low voltage in theannular volume 588 where resistive (semi-conductive) packer fluids maybe needed and are tolerable. These relatively small magnetic cores 532capture the magnetic field 551 from the current passing through andaround the core 532. Not all of the magnetic field 551 can beeffectively captured in most cases due to mechanical dimensions andproduct availability or custom sizes. However most applicationspresented by the design of a conventional well construct will allow apractical solution for systems (e.g., electrical devices 750, describedbelow) that require approximately ½ kW or less of continuous power.

FIG. 6 illustrates a close-up of a midstream portion of an isolated zone620, and is intended to show another case of the current 686 on tubing610 and inside the casing wall 609. The current sheets (sharing thedirection with the current 686 in the tubing 610) link magnetic couplers(toroidal cores 636 and 632) to that flow of current 686 such thatanywhere along the tubing 610 between core 636 and core 632, powerand/or communications access can be harvested for use by one or moreelectrical devices. The packer shorts 675 (in this case, short 675 a and675 b), which are each a short between the tubing 610 and the casing609, are shown in FIG. 6. These shorts 675 represent the boundaries ofthis completion cell 620 (zone 620), which creates a circuit closed loopwhere those currents 686 and corresponding current sheets are created bythe induced current from one magnetic core 636 and/or the other magneticcore 632.

The winding wires 657 of the core secondaries exit the zone 620 throughthe feedthrough 626 of the packer 624 to link to the next adjacent zone620 or cell 620. For example, winding wire 657 a acts as the secondarywrapped around core 636 and are disposed within the feedthrough 626 a ofthe packer 624 a to act as the secondary wrapped another core (e.g.,core 632 b) in an adjacent zone 620. As another example, winding wire657 b acts as the secondary wrapped around core 632 and are disposedwithin the feedthrough 626 b of the packer 624 b to act as the secondarywrapped another core (e.g., core 636 c) in an adjacent zone 620. Thissystem and process is replicated at each cell 620 or zone 620. It shouldbe noted that each winding wire 657 (e.g., winding wire 657 a) can be asingle continuous wire. Alternatively, a winding wire 657 can be twowires whose distal ends are joined together proximate to the core thatthey are wrapped around.

A completion system may have cable feed to a penetrated, top packer(e.g., packer 128) from the hanger. In cases where the top packer is aconsiderable distance down, this would eliminate the need forcentralizers and high resistance (insulating) packer fluids. Thefollowing (further downhole) production zones would then use the examplemagnetically coupled packer approach, such as shown and describedherein, for power and communication feed through the producing cells 620below (further downhole). Each zone 620 or electric cell 620 is treatedas autonomous from all neighboring cells 620 due to the packer/casingshorts 675 therebetween, where the only link or supply line is thewinding wires 657 disposed in the feedthrough 626 of each packer 624 tothe next cell 620.

FIG. 7 illustrates a close-up of a midstream portion of an isolated zone720, having an electrical device 750 (in this case, a sensor system)placed within the cell 720 or zone 720 along the tubing 710. Anelectrical device 750 can be any device that uses power to operateand/or communicate. Examples of an electrical device 750 can include,but are not limited to, a sensor (e.g., pressure, temperature, flow), asolenoid (e.g., for a valve), a switch, a battery, a capacitor, and arelay. The example system can be designed to transmit both operationalpower for active circuits and small motorized devices. Also, usingpower-conditioning, energy-storage techniques could invoke valve andother mechanical functions in each zone (e.g., zone 720) requiringsignificant, short-lived mechanical force.

In example embodiments, in addition to or in the alternative of a sensorsystem, the electrical device 750 can include a solenoid (for a valve),fluid identifying sensors, flow measuring devices, pressure sensors, andtemperature sensors. The electrical devices 750 can be placed at anylocation along the cell 720 or zone 720 along the tubing 710. In certainembodiments, the electrical device 750 can be a multitude of remotesensing and control devices located throughout the zone 720.

In some cases, as shown below with respect to FIG. 8, a zone 720 can bevery long and/or there are multiple electrical devices 750 spread outwithin the zone 720. In such a case, one or more of these electricaldevices 750 can be linked to the example power delivery system withinthe zone 720 via an additional core (e.g., core 736 b) and/or anotherwinding (e.g., winding 757 c) around a cell-terminating core (core 732)at a packer 724 or packer assembly, as applicable. An additional winding(e.g., winding 757 c) can be included on any of the cores (e.g., core736) in the zone 720, regardless of location (in the middle of thetubing 710, at a packer 724) of the core within the zone 720. Eachwinding (e.g., winding 757 a) can be of any number of turns toaccommodate the operation and voltage needs of electrical device 750coupled to and receiving power from the winding. Higher turns ratiocould be advantageous for a power conditioning unit where a relativelyhigh voltage will be capacitor-stored, for a necessary high-actionmechanical function.

The electrical devices 750 (e.g., sensors) may be placed anywhere in thezone 720 proximate to the tubing 710 and can be co-located with anydesired function. One or more of the electrical devices 750 can be partof a packer assembly, included at a packer core with an extra winding onthe packer core. The complexity of the electronics in a number of sensorpackages is only governed by the expected temperature range thoseelectronic devices will be exposed to. In short, if the environmentalthermal character of the zone is not extreme, highly complex,processor-based electronics could be an option as an electrical device750 for the string design. This would lend itself to individuallyaddressed sensor/valve stations along any zone section where thosefavorable thermal conditions exist.

In certain example embodiments, there can be multiple electrical devices750 in a zone (e.g., zone 720). In addition, or in the alternative,there can be multiple zones with one or more electrical devices 750. Insuch cases, each electrical device 750 can have an assigned serialcommunications address so that functions within a particular zone 720and/or between zones can be treated and/or interrogated individually ortotally. In certain applications, there may be a need to control contactor direct electrical conduction of tubing 710 to casing 709 in theinter-zone areas of tubing/casing discipline (tubing 710 centralizationin the wellbore). Mid-zone “shorts” 775 (between each of the packers726) between tubing 710 and casing 709 in a zone 720 can significantlyaffect the passage of power and signals to any following (downhole) coretransformers. Coatings and insulated centralizer techniques can be usedas part of the completions design plan to help improve the transmissionof power and signals using example embodiments.

FIG. 8 shows a schematic of a power delivery system 890 with three zones820, broken up to fit the page, according to an example embodiment.Referring to FIGS. 1-8, not shown in FIG. 8 are the usual insulatedcentralizers or indication of packer fluids. The system 890 of FIG. 8can transmit power and data in a subterranean wellbore duringcompletions and/or production operations in accordance with one or moreexample embodiments. The system 890 of FIG. 8 is substantially the sameas what is described above with respect to FIGS. 1-7, except asspecifically stated below. For the sake of brevity, the similaritieswill not be repeated herein below.

The example system 890 includes electrical equipment 850 located withinthree of the zones 820. In this case, zone 820 a is adjacent to zone 820b, which is adjacent to zone 820 c, which is adjacent to zone 820 d.Zone 820 a and zone 820 b are separated by a short 875 a through packer824 a. Zone 820 b and zone 820 c are separated by a short 875 b throughpacker 824 b. Zone 820 c and zone 820 d are separated by a short 875 cthrough packer 824 c. There is no electrical equipment within zone 820a. Electrical equipment 850 a is located in zone 820 b, electricalequipment 850 b is located in zone 820 c, and electrical equipment 850 cis located in zone 820 d.

Zone 820 b, zone 820 c, and zone 820 d each have three cores, meaningthat an extra core has been added to each of those zones, as describedwith respect to FIG. 7 could be a configuration of the system 890.Specifically, in zone 820 b, core 836 a is coupled to packer 824 a, core832 b is coupled to packer 824 b, and core 836 b is disposedtherebetween, adjacent to electrical device 850 a. In this way, core 836b can be used to provide power directly to electrical device 850 a basedon the current flowing through tubing 810 induced by and between core836 a and core 832 b.

In addition, in zone 820 c, core 836 c is coupled to packer 824 b, core832 c is coupled to packer 824 c, and core 836 d is disposedtherebetween, adjacent to electrical device 850 b. In this way, core 836d can be used to provide power directly to electrical device 850 b basedon the current flowing through tubing 810 induced by and between core836 c and core 832 c. Further, in zone 820 d, core 836 e is coupled topacker 824 c, another core (not shown) is coupled to another packer (notshown), and core 836 f is disposed therebetween, adjacent to electricaldevice 850 c. In this way, core 836 f can be used to provide powerdirectly to electrical device 850 c based on the current flowing throughtubing 810 induced by and between core 836 e and the additionaldownstream core. As an alternative to having a third core, as discussedabove with respect to FIG. 7, one of the cores (e.g., core 832 b)coupled to a packer (e.g., packer 824 b) can use an additional windingon the core above or below the electrical device (e.g., electricaldevice 850 a).

FIG. 9A shows a schematic of a packer assembly 970 an unset conditionand with embedded inductive coupling and electrical devices 950,according to an example embodiment. FIG. 9B shows a schematic of thepacker assembly 970 of FIG. 9A in a set condition according to anexample embodiment. Referring to FIGS. 1-9B, the components of thepacker assembly 970 are substantially the same as those described above,and for the sake of brevity, the similarities may not be repeatedherein. The packer assembly 970 is in an unset position because thepacker seals 967 are deflated, and the upper slip section 966 and thelower slip section 964 are retracted (not protracted). As a result,there is no pressure separation above and below the packer 924. In otherwords, the packer seals 967, the upper slip section 966, and the lowerslip section 964 of the packer 924 fail to contact the casing 909,allowing the cavity 988 to be substantially continuous (from a pressurestandpoint) along the length of the packer assembly 970, forming asingle zone 920.

Since the packer assembly 970 in this case has embedded inductivecoupling, core 932 is embedded into the top of the packer assembly 970,and core 936 is embedded into the bottom of the packer assembly 970.Core 932 and core 936 are coupled to each other by winding wires 957,which are disposed in the feedthrough 926 in the packer assembly 970 andare wound around core 932 and core 936. Electrical device 950 is alsoembedded into the bottom of the packer assembly 970 and is providedpower from winding wire 957 or a different winding wire wrapped aroundcore 936.

In FIG. 9B, the packer seals 967, the upper slip section 966, and thelower slip section 964 of the packer 924 are all expanded/protracted sothat they abut against the inner wall of the casing 909. As a result,zone 920 a is physically separated from zone 920 b, and a pressureseparation is created between the two zones 920. The upper slip section966 and the lower slip section 964 can be electrically-conductive andact as the cleats (not shown in FIGS. 9A and 9B) described above in thatthe slip sections can create a short with the casing 909. Alternatively,the packer assembly 970 can include a number of cleats to create theshorts that allow current flowing along the tubing 910 to return alongthe casing 909 within a zone 920 (e.g., zone 920 a, zone 920 b). Theelectrical device 950 can thus be used to measure temperature, pressure,flow, and/or other parameters in zone 920 b below the packer 924.

FIG. 10 shows a schematic of a single zone 1020 simulator that wastested in a laboratory to verify the practical use of the example systemof power and data transmission. A magnetic toroidal core 1032 and core1036 were placed at either end of the zone 1020, and coupled to thecurrent sheet in the tubing 1010-casing 1009 loop-current along the pathshown for current 1086. The electrical device 1050 receives powerinduced from core 1036 using winding wires 1057.

FIG. 11 shows a schematic of a dual-zone 1120 simulator that was testedin a non-idealized laboratory arrangement to measure power loss across azone 1120 b. A magnetic toroidal core 1132 a and core 1136 a were placedat either end of zone 1120 a, and coupled to the current sheet in thetubing 1110-casing 1109 loop-current along path shown for current 1186a. Similarly, a magnetic toroidal core 1132 b and core 1136 b wereplaced at either end of zone 1120 b, and coupled to the current sheet inthe tubing 1110-casing 1109 loop-current along the path shown forcurrent 1186 b.

Initial lab results indicate that a five-zone completion could provide10-15 watts at zone 1120 b with about 80 watts applied by the powersource 1195 (e.g., at the surface level). Specified custom made coresfor intended power and communication frequencies of a maximum OD,minimum ID design (as mechanically practicable), could increase theefficiency of the multi-zone system significantly (which was not donefor the laboratory tests). However, an optimized system could beemployed to supply power of about 0.5 KVA and below to an electricaldevice or devices using this example system and technique.

The systems, methods, and apparatuses described herein allow fortransmitting power and data within a wellbore. Supply of power usingmagnetic toroidal cores and existing wellbore hardware, such as a tubingstring and casing, reduces the need for conventional power cablingcompletion insertions within each zone of a wellbore. The application ofexample embodiments may employ relatively high current and moderatelyhigh voltage use of the well structure.

Although embodiments described herein are made with reference to exampleembodiments, it should be appreciated by those skilled in the art thatvarious modifications are well within the scope and spirit of thisdisclosure. Those skilled in the art will appreciate that the exampleembodiments described herein are not limited to any specificallydiscussed application and that the embodiments described herein areillustrative and not restrictive. From the description of the exampleembodiments, equivalents of the elements shown therein will suggestthemselves to those skilled in the art, and ways of constructing otherembodiments using the present disclosure will suggest themselves topractitioners of the art. Therefore, the scope of the exampleembodiments is not limited herein.

What is claimed is:
 1. A packer assembly for disposal within asubterranean wellbore lined by a casing, the packer assembly comprising:a packer comprising an upper end, a lower end, and a feedthrough thattraverses the packer from the upper end to the lower end, wherein theupper end is configured to couple to a first tubing string, wherein thelower end is configured to couple to a second tubing string; a firstcore disposed around the second tubing string adjacent to the lower endof the packer; and an electrical wire disposed within the feedthrough ofthe packer, wherein the electrical wire has a proximal end and a distalend wrapped around the first core, wherein the proximal end of theelectrical wire is configured to receive a first power from a powersource disposed above the upper end of the packer, wherein the distalend of the electrical wire is configured to use the first power toinduce a second power in the first core, wherein the second power in thefirst core generates a first current that flows on the second tubingstring away from the first core.
 2. The packer assembly of claim 1,wherein the power source comprises a second core disposed around thefirst tubing string adjacent to the upper end of the packer, wherein theproximal end of the electrical wire is wrapped around the second core.3. The packer assembly of claim 2, wherein the packer, the first core,the second core, and the electrical wire form a single integral piece.4. The packer assembly of claim 2, wherein the second core is configuredto receive a second current from a third core of an additional packerassembly, wherein the third core is disposed around the first tubingstring.
 5. The packer assembly of claim 1, wherein the proximal end ofthe electrical wire is coupled to a power source at a surface above thesubterranean wellbore.
 6. The packer assembly of claim 1, furthercomprising: at least one cleat disposed on an outer surface of a body ofthe packer, wherein the at least one cleat comprises electricallyconductive material and is configured to abut against a casing of thesubterranean wellbore, wherein the at least one cleat further haselectrical continuity with the second tubing string when the secondtubing string is coupled to the packer.
 7. The packer assembly of claim6, wherein the at least one cleat is retractable relative to the body ofthe packer.
 8. The packer assembly of claim 1, wherein the packercomprises a body, wherein the body has disposed thereon at least oneseal and at least one slip section, wherein the at least one seal andthe at least one slip section are configured to abut against a casing ofthe subterranean wellbore to provide a pressure separation within thesubterranean wellbore above the packer and the subterranean wellborebelow the packer.
 9. The packer assembly of claim 1, wherein the firstcore comprises magnetic properties.
 10. A power transmission system foruse within in a subterranean wellbore having a casing disposed against asubterranean formation and defining an outer perimeter of thesubterranean wellbore and forming a cavity, the system comprising: apower source disposed proximate to a surface at an opening of thesubterranean wellbore, wherein the power source generates a first power;a first tubing string segment disposed within the cavity; a first packermechanically coupled to a first distal end of the first tubing stringwithin the cavity of the subterranean wellbore, wherein the first packerhas a first feedthrough disposed therein along a first height of thefirst packer; a second tubing string segment mechanically coupled to afirst bottom end of the first packer within the cavity of thesubterranean wellbore; a first core disposed around the second tubingstring segment adjacent to the bottom end of the first packer and thefirst feedthrough; and a first electrical wire disposed within the firstfeedthrough of the first packer, wherein the first electrical wire has afirst end coupled to the power source and a second end wrapped aroundthe first core, wherein the first electrical wire receives the firstpower from the power source, wherein the first power flowing through thefirst electrical wire disposed around the first core induces a secondpower in the first core, wherein the second power in the first coregenerates a first current that flows on the second tubing string awayfrom the first core further into the subterranean wellbore.
 11. Thesystem of claim 10, wherein the first packer comprises a body, whereinthe body has disposed thereon at least one seal and at least one slipsection, wherein the at least one seal and the at least one slip sectionare configured to abut against the casing within the cavity of thesubterranean wellbore to provide a pressure separation within the cavityof the subterranean wellbore above the first packer and the subterraneanwellbore below the first packer.
 12. The system of claim 10, furthercomprising: a second core disposed around the second tubing stringsegment; and a second electrical wire wrapped around the second core,wherein the first current induces a third power in the second electricalwire.
 13. The system of claim 12, further comprising: at least one firstelectrical device coupled to the second electrical wire and disposedadjacent to the second core, wherein the at least one electrical deviceoperates using the third power.
 14. The system of claim 12, furthercomprising: a second packer coupled to a second distal end of the secondtubing string segment, wherein the second core and the at least oneelectrical device are disposed adjacent to the second packer, whereinthe second packer has a second feedthrough disposed therein along asecond height of the second packer, wherein the second electrical wireis disposed within the second feedthrough; a third tubing string segmentmechanically coupled to a second bottom end of the second packer withinthe cavity of the subterranean wellbore; and a third core disposedaround the second tubing string segment adjacent to the bottom end ofthe second packer and the second feedthrough, wherein the secondelectrical wire is further wrapped around the third core, wherein thethird power flowing through the second electrical wire disposed aroundthe third core induces a third power in the third core, wherein thethird power in the third core generates a second current that flows onthe third tubing string away from the third core further into thesubterranean wellbore.
 15. The system of claim 14, further comprising: afourth core disposed around the third tubing string segment; a thirdelectrical wire wrapped around the fourth core, wherein the secondcurrent induces a fourth power in the third electrical wire; and atleast one first electrical device coupled to the third electrical wireand disposed adjacent to the fourth core, wherein the at least oneelectrical device operates using the fourth power.
 16. The system ofclaim 14, wherein the second packer comprises at least one first cleatdisposed on a first outer surface of the second packer, wherein the atleast one first cleat comprises electrically conductive material andabuts against the casing.
 17. The system of claim 16, wherein thecasing, the second tubing string segment, and the third tubing stringsegment are electrically conductive, wherein the at least one firstcleat forms a first short that electrically isolates the second tubingstring segment from the third tubing string segment.
 18. The system ofclaim 17, wherein the first packer comprises at least one second cleatdisposed on a second outer surface of the first packer, wherein the atleast one second cleat comprises the electrically conductive materialand abuts against the casing, wherein the at least one second cleatforms a second short that electrically isolates the second tubing stringsegment from the first tubing string segment.
 19. The system of claim14, wherein the first current flows in a loop down the second tubingstring segment and up the casing between the first core and the secondcore.
 20. The system of claim 12, further comprising: a second packercoupled to a second distal end of the second tubing string segment; athird core disposed around the second tubing string segment toward asecond distal end of the second tubing string segment; a secondelectrical wire wrapped around the second core, wherein the firstcurrent induces a third power in the second electrical wire; and atleast one first electrical device coupled to the second electrical wireand disposed adjacent to the second core, wherein the at least oneelectrical device operates using the third power.